Fig. 3. (a) Measurement of isothermal absorption kinetics for the 10 wt% MgFe₂O₄-doped MgH₂ sample in the 2^nd, 4^th, 6^th, 8^th and 10^th cycle at 320 °C under 33.0 atm H₂ pressures and (b) measurement of isothermal desorption kinetics for the 10 wt% MgFe₂O₄-doped MgH₂ sample in the 2^nd, 4^th, 6^th, 8^th and 10^th cycle at 320 °C under 1.0 atm.